If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #2919
Joined: Fri Jun 11 2010, 06:30PM
Location: Cambridge, MA
Posts: 652
loveHV wrote ...
i'd really wish i had mini brick IGBT's. Those things are much more robust.
bah, minibricks are overrated...have you looked into the new field stop IGBT's from Fairchild? I've been running the FGH60N60SMD at 300A in a half-bridge, and Steve Ward uses them in his QCW Tesla gun, and apparently they're pretty hardy. If you're worried about thermal issues you can always float your heatsinks, or use exotic thermal insulators (I've seen alumina thermal pad somewhere).
Registered Member #1854
Joined: Wed Dec 10 2008, 06:09PM
Location: West-Flanders Belgium
Posts: 88
Well the type of IGBT you're talking about can handle 180A pulsed. So i guess as mine can handle 220A pulsed it shouldn't be a problem to run them to the max. (before the overvoltage kills my MMC).
It all comes down how close i am to Zero Current Switching. And how fast i can dissipate the heat. Those mini bricks conduct heat better from the silicon to the case and from the case to the heatsink (larger surface).
So if i am able to perfect the cooling system for my H-bridge i should get similar results, if those mini bricks are so over rated as you say they are :p .
Lets hope for the best :) I'll post pics on the add your tesla coil topic if i get the coil up and running.
Registered Member #2292
Joined: Fri Aug 14 2009, 05:33PM
Location: The Wild West AKA Arizona
Posts: 795
loveHV wrote ...
And how fast i can dissipate the heat. Those mini bricks conduct heat better from the silicon to the case and from the case to the heatsink (larger surface).
This is not unnecessary true, because SOT-227 have electrical isolation of the backplate this adds another layer of thermal resistance for die to case. In most cases this makes the thermal impedance of the SOT-227 higher than what you mite find with a TO-247 variant that has a direct die to case connection.
Be sure check the thermal constant in the datasheet for both the SOT-227 and TO-247 for the die you are using.
Registered Member #1854
Joined: Wed Dec 10 2008, 06:09PM
Location: West-Flanders Belgium
Posts: 88
I looked it up for 2 IGBT's.
The "legendary" HGT1N40N60A4D minibrick has a thermal constant of 0.42°C/W from junction to case.
While the IRG4PC50UD TO-247 has a thermal constant of 0.65°C/W from junction to case.
lets say they both dissipate 30W (power of a small soldering iron). The junction of the minibrick will be 12,6°C warmer then the case whilst the junction of the TO-247 will be 19,5°C warmer. Its a small difference. But still, the mini brick has the edge.
Also the minibrick doesn't need to be insulated from the heatsink, the TO-247 does if the entire H-bridge IGBT's are mounted on one heatsink.
This gives more advantage towards a mini-brick.
I just took 2 random IGBT's this means that the constant might change depending on the type. I know that the IRG4PC50UD has one of the best TO-247 thermal impedance. Other TO-247 will likely have a bigger thermal impedance. like the FGA40N60UFD for example.
But thanks for enlighting me that the thermal difference between the two case styles isn't all that different. :) But the brick still has the edge :p (if i look at my examples)
Registered Member #1854
Joined: Wed Dec 10 2008, 06:09PM
Location: West-Flanders Belgium
Posts: 88
Dr. Dark Current wrote ...
The HGTG40N60A4 (TO247 version) has 0.2 K/W from junction to case, compare to HGT1N40N60A4D minibrick...
Then i withdraw my previous statement :p
For the record: (don't know if im saying this right :p )
I tried to find the TO247 version of the minibrick but i always landed on a datasheet of the minibrick version. So i got another datasheet, the "best bang for buck" IGBT for DRSSTC's according to HVwiki.
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
Comment on my H - bridge design please
